<template>
    <div class="component-upload-image">
        <el-upload
                multiple
                :action="uploadImgUrl"
                list-type="picture-card"
                :on-success="handleUploadSuccess"
                :before-upload="handleBeforeUpload"
                :limit="limit"
                :on-error="handleUploadError"
                :on-exceed="handleExceed"
                ref="imageUpload"
                :before-remove="handleDelete"
                :show-file-list="true"
                :headers="headers"
                :file-list="fileList"
                :on-preview="handlePictureCardPreview"
                :class="{ hide: fileList.length >= limit }"
        >
            <el-icon class="avatar-uploader-icon">
                <plus/>
            </el-icon>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip">
            请上传
            <template v-if="fileSize">
                大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
            </template>
            <template v-if="fileType">
                格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
            </template>
            的文件
        </div>
        
        <el-dialog
                v-model="dialogVisible"
                title="预览"
                width="800px"
                append-to-body
        >
            <img
                    :src="dialogImageUrl"
                    style="display: block; max-width: 100%; margin: 0 auto"
            />
        </el-dialog>
    </div>
</template>

<script setup>
    import {getToken} from "@/utils/auth";
    
    const props = defineProps({
        modelValue: [String, Object, Array],
        // 图片数量限制
        limit: {
            type: Number,
            default: 5,
        },
        // 大小限制(MB)
        fileSize: {
            type: Number,
            default: 5,
        },
        // 文件类型, 例如['png', 'jpg', 'jpeg']
        fileType: {
            type: Array,
            default: () => ["png", "jpg", "jpeg"],
        },
        // 是否显示提示
        isShowTip: {
            type: Boolean,
            default: true
        },
    });
    
    const {proxy} = getCurrentInstance();
    const emit = defineEmits();
    const number = ref(0);
    const uploadList = ref([]);
    const dialogImageUrl = ref("");
    const dialogVisible = ref(false);
    const baseUrl = import.meta.env.VITE_APP_BASE_API;
    const uploadImgUrl = ref(import.meta.env.VITE_APP_BASE_API + "/common/upload"); // 上传的图片服务器地址
    const headers = ref({Authorization: "Bearer " + getToken()});
    const fileList = ref([]);
    const showTip = computed(
            () => props.isShowTip && (props.fileType || props.fileSize)
    );
    
    watch(() => props.modelValue, val => {
        if (val) {
            // 首先将值转为数组
            const list = Array.isArray(val) ? val : props.modelValue.split(",");
            // 然后将数组转为对象数组
            fileList.value = list.map(item => {
                if (typeof item === "string") {
                    if (item.indexOf(baseUrl) === -1 && item.indexOf("http") === -1) {
                        item = {name: baseUrl + item, url: baseUrl + item};
                    } else {
                        item = {name: item, url: item};
                    }
                }
                return item;
            });
        } else {
            fileList.value = [];
            return [];
        }
    }, {deep: true, immediate: true});
    
    // 上传前loading加载
    function handleBeforeUpload(file) {
        let isImg = false;
        if (props.fileType.length) {
            let fileExtension = "";
            if (file.name.lastIndexOf(".") > -1) {
                fileExtension = file.name.slice(file.name.lastIndexOf(".") + 1);
            }
            isImg = props.fileType.some(type => {
                if (file.type.indexOf(type) > -1) return true;
                if (fileExtension && fileExtension.indexOf(type) > -1) return true;
                return false;
            });
        } else {
            isImg = file.type.indexOf("image") > -1;
        }
        if (!isImg) {
            proxy.$modal.msgError(
                    `文件格式不正确, 请上传${props.fileType.join("/")}图片格式文件!`
            );
            return false;
        }
        if (props.fileSize) {
            const isLt = file.size / 1024 / 1024 < props.fileSize;
            if (!isLt) {
                proxy.$modal.msgError(`上传头像图片大小不能超过 ${props.fileSize} MB!`);
                return false;
            }
        }
        proxy.$modal.loading("正在上传图片，请稍候...");
        number.value++;
    }
    
    // 文件个数超出
    function handleExceed() {
        proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
    }
    
    // 上传成功回调
    function handleUploadSuccess(res, file) {
        if (res.code === 200) {
            uploadList.value.push({name: res.fileName, url: res.fileName});
            uploadedSuccessfully();
        } else {
            number.value--;
            proxy.$modal.closeLoading();
            proxy.$modal.msgError(res.msg);
            proxy.$refs.imageUpload.handleRemove(file);
            uploadedSuccessfully();
        }
    }
    
    // 删除图片
    function handleDelete(file) {
        const findex = fileList.value.map(f => f.name).indexOf(file.name);
        if (findex > -1 && uploadList.value.length === number.value) {
            fileList.value.splice(findex, 1);
            emit("update:modelValue", listToString(fileList.value));
            return false;
        }
    }
    
    // 上传结束处理
    function uploadedSuccessfully() {
        if (number.value > 0 && uploadList.value.length === number.value) {
            fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
            uploadList.value = [];
            number.value = 0;
            emit("update:modelValue", listToString(fileList.value));
            proxy.$modal.closeLoading();
        }
    }
    
    // 上传失败
    function handleUploadError() {
        proxy.$modal.msgError("上传图片失败");
        proxy.$modal.closeLoading();
    }
    
    // 预览
    function handlePictureCardPreview(file) {
        dialogImageUrl.value = file.url;
        dialogVisible.value = true;
    }
    
    // 对象转成指定字符串分隔
    function listToString(list, separator) {
        let strs = "";
        separator = separator || ",";
        for (let i in list) {
            if (undefined !== list[i].url && list[i].url.indexOf("blob:") !== 0) {
                strs += list[i].url.replace(baseUrl, "") + separator;
            }
        }
        return strs != "" ? strs.substr(0, strs.length - 1) : "";
    }
</script>

<style scoped lang="scss">
    // .el-upload--picture-card 控制加号部分
    :deep(.hide .el-upload--picture-card) {
        display: none;
    }
</style>